<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>圆角边框</title>
    <style>
        .box {
            height: 300px;
            width: 500px;
            background-color: pink;
            margin: 100px auto;
            border-radius: 10px;
            /* border-radius: 10px；圆角边框,数值越大弧度越大 */
        }
    </style>
</head>

<body>
    <div class="box"></div>
</body>

</html>